"""Shared e2e harness: free ports, health waits, lfx spawn, migrate, sessions.

Single place for logic duplicated between tests/conftest.py and
scripts/smoke_e2e.py (~60 lines). Full real-LFX runs are kept.
"""

from __future__ import annotations

import os
import shutil
import socket
import subprocess
import sys
import time
import urllib.request
from pathlib import Path


def free_port() -> int:
    sock = socket.socket()
    sock.bind(("127.0.0.1", 0))
    port = sock.getsockname()[1]
    sock.close()
    return port


def wait_healthy(url: str, deadline_s: float = 240.0) -> None:
    deadline = time.time() + deadline_s
    while time.time() < deadline:
        try:
            with urllib.request.urlopen(url + "/health", timeout=3) as response:
                if response.status == 200:
                    return
        except OSError:
            time.sleep(1)
    raise RuntimeError(f"server did not become healthy: {url}")


def spawn_lfx(flow_dir: Path, port: int) -> subprocess.Popen:
    bindir = Path(sys.executable).parent
    lfx_bin = shutil.which("lfx", path=str(bindir)) or "lfx"
    env = {**os.environ, "LANGFLOW_API_KEY": "", "LFX_API_KEY": "test-lfx-key"}
    return subprocess.Popen(
        [
            lfx_bin,
            "serve",
            "--host",
            "127.0.0.1",
            "--port",
            str(port),
            "--flow-dir",
            str(flow_dir),
            str(flow_dir),
        ],
        stdout=subprocess.PIPE,
        stderr=subprocess.STDOUT,
        text=True,
        env=env,
    )


def migrate_throwaway(backend_dir: Path) -> None:
    from alembic import command as alembic_command
    from alembic.config import Config

    cfg = Config()
    cfg.set_main_option("script_location", str(backend_dir / "migrations"))
    alembic_command.upgrade(cfg, "head")